The present technology relates to optical devices for transmitting and receiving light through optical fibers and more particularly to alignment and positioning of optical fibers to improve the accuracy of the transmission or reception of light through optical fibers.
Optical fibers are often grouped together into assemblies in which the fibers extend generally parallel to each other, i.e., in what are often termed “pigtail assemblies,” and terminate within housings that align one of the ends of the optical fibers. Such assemblies have a variety of uses, including power monitoring of optical network systems. In one example, fibers within one part of a housing are inserted within grooves carved along an axis of the housing such that the fibers are separated from each other. The grooves are formed by two walls defining triangular cross-sections such that the fibers self-align when portions of the fibers contact each of the two walls. The other part of the housing is a flat plate that compresses the optical fibers upon assembly with the grooved part of the housing. In this configuration, dimensional tolerances within each of the carved grooves as well as the optical fibers themselves may accumulate to add to misalignment of the optical fibers upon assembly of the fibers in the housing.
In another example, a one-piece housing has an aperture that groups ends of optical fibers together into an assembly such that the fibers are in contact with each other. The aperture has four walls that form a square shape. To form the assembly, the fibers are inserted within the fixed size of the aperture of the housing such that the dimensional tolerances of the walls determine the alignment of the fibers as the fibers. In this manner, the fibers are either tightly or loosely inserted into the housing.
In some instances, each of these examples of pigtail assemblies uses one optical fiber of an optical fiber pair to transmit light through a lens assembly to a sensor, such as a photodiode. The corresponding optical fiber of the pair receives a part of the light that is reflected back from the lens assembly. The alignment of the fibers in these pigtail assemblies may be sufficient for a single sensor but do not provide adequate alignment of multiple pairs of optical fibers to be used to direct light through a single lens assembly to multiple sensors, such as may be contained in a photodiode array semiconductor chip.
Therefore, there exists a need for improving the alignment of multiple pairs of optical fibers within an assembly of such fibers.